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Quiz – Chemical equations

Do you feel confident about writing balanced equations for chemical reactions? Test yourself with a quiz.

Your turn – chemical equations

For questions 1—5, identify the reactants and products in the chemical equations.

  1. \(\ce{2H}_{2}+\ce{O}_{2}\rightarrow2\ce{H}_{2}\ce{O}\)

Reactants: \(\ce{H}_{2}\) and \(\ce{O}_{2}\)

Products: \(\ce{H}_{2}\ce{O}\)

  1. \(\ce{CH}_{4}+2\ce{O}_{2}\rightarrow\ce{CO}_{2}+\ce{H}_{2}\ce{O}\)

Reactants: \(\ce{CH}_{4}\) and \(\ce{O}_{2}\)

Products: \(\ce{CO}_{2}\) and \(\ce{H}_{2}\ce{O}\)

  1. \(2\ce{Fe}_{2}\ce{O}_{3}+3\ce{C}\rightarrow4\ce{Fe}+3\ce{CO}_{2}\)

Reactants: \(\ce{Fe}_{2}\ce{O}_{3}\) and \(\ce{C}\)

Products: \(\ce{Fe}\) and \(\ce{CO}_{2}\)

  1. \(\left(\ce{NH}_{4}\right)_{2}\ce{Cr}_{2}\ce{O}_{7}\rightarrow\ce{Cr}_{2}\ce{O}_{3}+4\ce{H}_{2}\ce{O}+\ce{N}_{2}\)

Reactants: \(\left(\ce{NH}_{4}\right)_{2}\ce{Cr}_{2}\ce{O}_{7}\)

Products: \(\ce{Cr}_{2}\ce{O}_{3}\) , \(\ce{H}_{2}\ce{O}\) and \(\ce{N}_{2}\)

  1. \(\ce{CaCO}_{3}\rightarrow\ce{CaO}+\ce{CO}_{2}\)

Reactants: \(\ce{CaCO}_{3}\)

Products: \(\ce{CaO}\) and \(\ce{CO}_{2}\)

For questions 6—10, write balanced equations for the chemical reactions.

  1. Ammonia gas reacts with oxygen gas to produce nitrogen gas and water.

\(4\ce{NH}_{3}(\textrm{g})+3\ce{O}_{2}(\textrm{g})\rightarrow2\ce{N}_{2}(\textrm{g})+6\ce{H}_{2}\ce{O}(\textrm{l})\)

  1. Solid sodium sulfate reacts with solid elemental carbon to produce solid sodium sulfite and carbon dioxide gas.

\(\ce{Na}_{2}\ce{SO}_{4}(\textrm{s})+2\ce{C}(\textrm{s})\rightarrow\ce{Na}_{2}\ce{S}(\textrm{s})+2\ce{CO}_{2}(\textrm{g})\)

  1. Solid elemental iron reacts with oxygen gas to produce solid ferric oxide.

\(4\ce{Fe}(\textrm{s})+3\ce{O}_{2}(\textrm{g})\rightarrow2\ce{Fe}_{2}\ce{O}_{3}(\textrm{s})\)

  1. Solid ammonium chloride separates into ammonia and hydrogen chloride gas.

\(\ce{NH}_{4}\ce{Cl}(\textrm{s})\rightarrow\ce{NH}_{3}(\textrm{g})+\ce{HCl}(\textrm{g})\)

  1. Gaseous hydrogen iodide decomposes into iodine gas and hydrogen gas.

\(2\ce{HI}(\textrm{g})\rightarrow\ce{H}_{2}(\textrm{g})+\ce{I}_{2}(\textrm{g})\)

For questions 11—22, balance the equations.

  1. \(\ce{FeI}_{2}(\textrm{s})+\ce{Cl}_{2}(\textrm{g})\rightarrow\ce{FeCl}_{3}(\textrm{s})+\ce{I}_{2}(\textrm{s})\)

\(2\ce{FeI}_{2}(\textrm{s})+3\ce{Cl}_{2}(\textrm{g})\rightarrow2\ce{FeCl}_{3}+2\ce{I}_{2}(\textrm{s})\)

  1. \(\ce{Fe}_{2}\ce{O}_{3}(\textrm{s})+\ce{C}(\textrm{s})\rightarrow\ce{Fe}(\textrm{s})+\ce{CO}_{2}(\textrm{g})\)

\(2\ce{Fe}_{2}\ce{O}_{3}(\textrm{s})+3\ce{C}(\textrm{s})\rightarrow4\ce{Fe}(\textrm{s})+3\ce{CO}_{2}(\textrm{g})\)

  1. \(\ce{HNO}_{3}(\textrm{l})+\ce{H}_{2}\ce{S}(\textrm{g})\rightarrow\ce{NO}(\textrm{g})+\ce{S}(\textrm{s})+\ce{H}_{2}\ce{O}(\textrm{l})\)

\(2\ce{HNO}_{3}(\textrm{l})+3\ce{H}_{2}\ce{S}(\textrm{g})\rightarrow2\ce{NO}(\textrm{g})+3\ce{S}(\textrm{s})+4\ce{H}_{2}\ce{O}(\textrm{l})\)

  1. \(\ce{SO}_{2}(\textrm{g})+\ce{H}_{2}\ce{O}(\textrm{l})\rightarrow\ce{H}_{2}\ce{SO}_{3}(\textrm{aq})\)

\(\ce{SO}_{2}(\textrm{g})+\ce{H}_{2}\ce{O}(\textrm{l})\rightarrow\ce{H}_{2}\ce{SO}_{3}(\textrm{aq})\)

  1. \(\ce{AgNO}_{3}(\textrm{aq})+\ce{KCl}(\textrm{aq})\rightarrow\ce{KNO}_{3}(\textrm{aq})+\ce{AgCl}(\textrm{s})\)

\(\ce{AgNO}_{3}(\textrm{aq})+\ce{KCl}(\textrm{aq})\rightarrow\ce{KNO}_{3}(\textrm{aq})+\ce{AgCl}(\textrm{s})\)

  1. \(\ce{PCl}_{3}(\textrm{l})+\ce{H}_{2}(\textrm{g})\rightarrow\ce{PH}_{3}(\textrm{g})+\ce{HCl}(\textrm{g})\)

\(\ce{PCl}_{3}(\textrm{l})+3\ce{H}_{2}(\textrm{g})\rightarrow\ce{PH}_{3}(\textrm{g})+3\ce{HCl}(\textrm{g})\)

  1. \(\ce{PbO}(\textrm{s})+\ce{NH}_{3}(\textrm{g})\rightarrow\ce{Pb}(\textrm{s})+\ce{N}_{2}(\textrm{g})+\ce{H}_{2}\ce{O}(\textrm{l})\)

\(3\ce{PbO}(\textrm{s})+2\ce{NH}_{3}(\textrm{g})\rightarrow3\ce{Pb}(\textrm{s})+\ce{N}_{2}(\textrm{g})+3\ce{H}_{2}\ce{O}(\textrm{l})\)

  1. \(\ce{NaClO}_{3}(\textrm{s})\rightarrow\ce{NaCl}(\textrm{s})+\ce{O}_{2}(\textrm{g})\)

\(2\ce{NaClO}_{3}(\textrm{s})\rightarrow2\ce{NaCl}(\textrm{s})+3\ce{O}_{2}(\textrm{g})\)

  1. \(\ce{N}_{2}\ce{O}(\textrm{g})\rightarrow\ce{N}_{2}(\textrm{g})+\ce{O}_{2}(\textrm{g})\)

\(2\ce{N}_{2}\ce{O}(\textrm{g})\rightarrow2\ce{N}_{2}(\textrm{g})+\ce{O}_{2}(\textrm{g})\)

  1. \(\ce{NH}_{4}\ce{NO}_{3}(\textrm{s})\rightarrow\ce{N}_{2}(\textrm{g})+\ce{O}_{2}(\textrm{g})+\ce{H}_{2}\ce{O}(\textrm{g})\)

\(2\ce{NH}_{4}\ce{NO}_{3}(\textrm{s})\rightarrow2\ce{N}_{2}(\textrm{g})+\ce{O}_{2}(\textrm{g})+4\ce{H}_{2}\ce{O}(\textrm{g})\)

  1. \(\ce{Mn}_{2}\left(\ce{CO}_{3}\right)_{3}(\textrm{s})\rightarrow\) \(\ce{Mn}_{2}\ce{O}_{3}(\textrm{s})+\ce{CO}_{2}(\textrm{g})\)

\(\ce{Mn}_{2}\left(\ce{CO}_{3}\right)_{3}(\textrm{s})\rightarrow\ce{Mn}_{2}\ce{O}_{3}(\textrm{s})+3\ce{CO}_{2}(\textrm{g})\)

  1. \(\ce{Na2CO3}(\textrm{aq})+\ce{Mg(NO3)2}(\textrm{aq})\rightarrow\ce{MgCO3}(\textrm{s}) +\ce{NaNO3}(\textrm{aq})\)

\(\ce{Na2CO3}(\textrm{aq})+\ce{Mg(NO3)2}(\textrm{aq})\rightarrow\ce{MgCO3}(\textrm{s})+2\ce{NaNO3}(\textrm{aq})\)

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